Systems and methods for a navigational device with improved route calculation capabilities

ABSTRACT

Systems, devices and methods are provided for an improved navigational route planning device which provides more understandable, accurate and timely route calculation capabilities. The navigational aid device with route calculation capabilities includes a processor connected to a memory. The memory includes cartographic data and a desired destination, the cartographic data including data indicative of thoroughfares of a plurality of types. A display is connected to the processor and is capable of displaying the cartographic data. The device is adapted to calculate a route to navigate to the desired destination. And, the device is adapted to adjust a starting point for the route calculation to an appropriate location such that the device is on the route at a time when the route calculation is completed. The device processes travel along the route, recognizes when the device has deviated from the route, and calculates a new route to navigate to the desired destination.

FIELD OF THE INVENTION

The present invention relates generally to navigational devices, and inparticular to navigational devices with improved route calculationcapabilities.

BACKGROUND OF THE INVENTION

Route planning devices are well known in the field of navigationalinstruments. The method of route planning implemented by known prior artsystems depends on the capabilities of system resources, such asprocessor speed and the amount and speed of memory. As increased systemcapability also increases system cost, the method of route planningimplemented by a navigation device is a function of overall system cost.

One feature of increased system capability involves off-routerecalculation capabilities. Many conventional navigational devicessimply do not incorporate an off-route recalculation functionality inorder to reduce system complexity and maintain a low overall systemcost. Some of these devices may alert the user that they are off course,but they do not perform any course recalculation. In these devices, theuser must halt their journey or attempt to relocate themselves on theprior planned route via traditional navigation methods, e.g. askingdirections or using a conventional map. With some devices, the user maystill be able to see the previously planned route, but the user willhave to employ his or her own decision making to chart back onto thedisplayed route. This can be time consuming and provide frustration to auser who is likely unfamiliar with the routes surrounding their errantlocation.

Additionally, in order to calculate a route it is necessary to select astarting position to begin the route calculation. The route calculationalgorithm invariably takes a small but finite amount of time, maybe onthe order of 10 to 20 seconds. If the current position of the device isused as the starting position for the route calculation, a new route isgenerated based on the position that was known historically. Thus, amoving device will have traveled some distance beyond that historicalposition. In other words, the new route will have a starting point whichcorresponds to the historical position which may or may not correspondto the device's current position. Thus, if a turn or other maneuver isindicated as a function of getting from the historical position (asknown at the time the calculation was started) to a given destination,the device will easily be beyond the turn that was generated by theroute calculation algorithm.

While stopping travel during the route calculation process may solve thestated problem of generating a route while in motion, in many caseshalting travel is not a viable alternative. For example, when the useris traveling on an interstate it is entirely impossible to simply stop.The alternative of pulling off on the shoulder of a road is undesirableand can be dangerous. Pulling off on an exit is equally undesirablesince doing so increases travel time and provides an added inconvenienceto the user. In other instances, such as navigating downtown citystreets, the traffic issues alone may prevent the user from stopping hisor her vehicle during the recalculation process. Even if the user hasthe ability to safely stop his or her vehicle, such as when traveling ina neighborhood, the inconvenience factor is present.

In summary, current prior art systems have created a spectrum ofproducts in which the degree of navigational accuracy is dictatedprimarily by the cost of the system. The lower cost systems currentlyoffer a low degree of accuracy that is often inadequate for users.Therefore, there exists a need for a navigational route planning devicewhich is more efficient and accurate than current low cost systems,without requiring more expensive system resources. In addition, there isalso a need for a navigational route planning device which provides auser with more understandable, accurate and timely route calculationcapabilities.

SUMMARY OF THE INVENTION

The above mentioned problems of navigational devices are addressed bythe present invention and will be understood by reading and studying thefollowing specification. Systems and methods are provided for anavigational route planning device which is more efficient and accuratethan current low cost systems, without requiring the more expensivesystem resources. The systems and methods of the present invention offeran improved navigational route planning device which provides a userwith more understandable, accurate and timely route calculationcapabilities.

In one embodiment of the present invention, an electronic navigationalaid device with improved route calculation capabilities is provided. Thenavigational aid device includes a processor with a display connected tothe processor. A memory is connected to the processor as well. Thememory includes cartographic data and a route to a desired destinationstored therein. The cartographic data includes data indicative ofthoroughfares of a plurality of types. The device processes travel alongthe route. The device is capable of selecting an appropriate startingpoint for a route calculation and capable of recognizing when the devicehas deviated from a route. When the device is off-route, the devicecalculates a new route to navigate to the desired destination. In orderto select an appropriate starting point for the route calculation orrecalculation, the device adjusts a starting point for the new route toa location forward along a current thoroughfare on which the device islocated or traveling such that the device is on the route at a time whenthe new route calculation is completed.

These and other embodiments, aspects, advantages, and features of thepresent invention will be set forth in part in the description whichfollows, and in part will become apparent to those skilled in the art byreference to the following description of the invention and referenceddrawings or by practice of the invention. The aspects, advantages, andfeatures of the invention are realized and attained by means of theinstrumentalities, procedures, and combinations particularly pointed outin the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a representative view of a Global Positioning System (GPS);

FIGS. 2A and 2B illustrate views for one embodiment of an electronicnavigational device according to the teachings of the present invention;

FIGS. 3A-3C illustrate views for another embodiment of an electronicnavigational device according to the teachings of the present invention;

FIG. 4A is a block diagram of one embodiment for the electroniccomponents within the hardware of FIGS. 2A-2B according to the teachingsof the present invention;

FIG. 4B is a block diagram of one embodiment for the electroniccomponents within the hardware of FIGS. 3A-3C according to the teachingsof the present invention;

FIG. 5 is a block diagram of a navigation system according to theteachings of the present invention;

FIG. 6 is a flow diagram of one embodiment of a navigation aid methodaccording to the teachings of the present invention; and

FIG. 7 is a flow diagram of another embodiment of a navigation aidmethod according to the teachings of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

In the following detailed description of the invention, reference ismade to the accompanying drawings which form a part hereof, and in whichis shown, by way of illustration, specific embodiments in which theinvention may be practiced. The embodiments are intended to describeaspects of the invention in sufficient detail to enable those skilled inthe art to practice the invention. Other embodiments may be utilized andchanges may be made without departing from the scope of the presentinvention. The following detailed description is, therefore, not to betaken in a limiting sense, and the scope of the present invention isdefined only by the appended claims, along with the full scope ofequivalents to which such claims are entitled.

The present invention is drawn to navigational systems and deviceshaving route calculation capabilities. One type of navigational systemincludes Global Positioning Systems (GPS). Such systems are known andhave a variety of uses. In general, GPS is a satellite-based radionavigation system capable of determining continuous position, velocity,time, and in some instances direction information for an unlimitednumber of users. Formally known as NAVSTAR, the GPS incorporates aplurality of satellites which orbit the earth in extremely preciseorbits. Based on these precise orbits, GPS satellites can relay theirlocation to any number of receiving units.

The GPS system is implemented when a device specially equipped toreceive GPS data begins scanning radio frequencies for GPS satellitesignals. Upon receiving a radio signal from a GPS satellite, the devicecan determine the precise location of that satellite via one ofdifferent conventional methods. The device will continue scanning forsignals until it has acquired at least three different satellitesignals. Implementing geometric triangulation, the receiver utilizes thethree known positions to determine its own two-dimensional positionrelative to the satellites. Additionally, acquiring a fourth satellitesignal will allow the receiving device to calculate itsthree-dimensional position by the same geometrical calculation. Thepositioning and velocity data can be updated in real time on acontinuous basis by an unlimited number of users.

FIG. 1 is representative of a GPS denoted generally by reference numeral100. A plurality of satellites 120 are in orbit about the Earth 124. Theorbit of each satellite 120 is not necessarily synchronous with theorbits of other satellites 120 and, in fact, is likely asynchronous. AGPS receiver device 140 of the present invention is shown receivingspread spectrum GPS satellite signals 160 from the various satellites120.

The spread spectrum signals 160 continuously transmitted from eachsatellite 120 utilize a highly accurate frequency standard accomplishedwith an extremely accurate atomic clock. Each satellite 120, as part ofits data signal transmission 160, transmits a data stream indicative ofthat particular satellite 120. It will be appreciated by those skilledin the relevant art that the GPS receiver device 140 must acquire spreadspectrum GPS satellite signals 160 from at least three satellites 120for the GPS receiver device 140 to calculate its two-dimensionalposition by triangulation. Acquisition of an additional signal 160,resulting in signals 160 from a total of four satellites 120, permitsGPS receiver device 140 to calculate its three-dimensional position.

FIGS. 2A and 2B illustrate views for one embodiment of an electronicnavigational device 230 according to the teachings of the presentinvention. As one of ordinary skill in the art will understand uponreading this disclosure, the device can be portable and can be utilizedin any number of implementations such as automobile, personal marinecraft, and avionic navigation. In the embodiment of FIG. 2A a front viewof the navigational device 230 is provided showing the navigationaldevice has a generally rectangular housing 232. The housing 232 isconstructed of resilient material and has been rounded for aesthetic andergonomic purposes. As shown in FIG. 2A, the control face 234 has accessslots for an input key pad 238, other individual keys 239, and a displayscreen 236. In one embodiment, the display screen 236 is a LCD displaywhich is capable of displaying both text and graphical information. Theinvention, however, is not so limited. Audio information can likewise beprovided in one embodiment.

In FIG. 2B, a side view of the navigational device 230 is provided. FIG.2B illustrates that the device's housing 232 is defined by an outerfront case 240 and a rear case 242. As shown in FIG. 2B, the outer frontcase 240 is defined by the control face 234. In the embodiment shown inFIG. 2B, the outer front case 240 and the rear case 242 are made of onemolded piece to form the device housing 232 and support input key pad238, other individual keys 239, and display screen 236 in respectiveaccess slots shown in the control face 234 of FIG. 2A.

FIGS. 3A-3C illustrate views for another embodiment of an electronicnavigational device 310 according to the teachings of the presentinvention. The navigational device 310 shown in FIGS. 3A-3C includes apersonal digital assitant (PDA) with integrated GPS receiver andcellular transceiver according to the teachings of the presentinvention. The GPS integrated PDA operates with an operating system (OS)such as, for example, the well-known Palm or Pocket PC operatingsystems, or the lesser-used Linux OS. As shown in the top view of FIG.3A, the GPS integrated PDA 310 includes an internal integrated GPS patchantenna 314 and a cellular transceiver 316 contained in a housing 318.The housing 318 is generally rectangular with a low profile and has afront face 320 extending from a top end 322 to a bottom end 324. Mountedon front face 320 is a display screen 326, which is touch sensitive andresponsive to a stylus 330 (shown stored in the side view of FIG. 3B) ora finger touch. FIGS. 3A-3C illustrate the stylus 330 nested withinhousing 318 for storage and convenient access in a conventional manner.The embodiment shown in FIG. 3A illustrates a number of control buttons,or input keys 328 positioned toward the bottom end 324. The invention,however, is not so limited and one of ordinary skill in the art willappreciate that the input keys 328 can be positioned toward the top end322 or at any other suitable location. The end view of FIG. 3Cillustrates a map data cartridge bay slot 332 and headphone jack 334provided at the top end 322 of the housing 318. Again, the invention isnot so limited and one of ordinary skill in the art will appreciate thata map data cartridge bay slot 332 and headphone jack 334 can be providedat the bottom end 324, separately at opposite ends, or at any othersuitable location.

It should be understood that the structure of GPS integrated PDA 310 isshown as illustrative of one type of integrated PDA navigation device.Other physical structures, such as a cellular telephone and avehicle-mounted unit are contemplated within the scope of thisinvention.

FIGS. 2A-2B and 3A-3C are provided as illustrative examples of hardwarecomponents for a navigational device according to the teachings of thepresent invention. However, the invention is not limited to theconfiguration shown in FIGS. 2A-2B and 3A-3C. One of ordinary skill inthe art will appreciate other suitable designs for a hardware devicewhich can accommodate the present invention.

FIG. 4A is a block diagram of one embodiment for the electroniccomponents within the hardware of FIGS. 2A-2B, such as within housing232 and utilized by the electronic navigational device. In theembodiment shown in FIG. 4A, the electronic components include aprocessor 410 which is connected to an input 420, such as keypad vialine 425. It will be understood that input 420 may alternatively be amicrophone for receiving voice commands. Processor 410 communicates withmemory 430 via line 435. Processor 410 also communicates with displayscreen 440 via line 445. An antenna/receiver 450, such as a GPSantenna/receiver is connected to processor 410 via line 455. It will beunderstood that the antenna and receiver, designated by referencenumeral 450, are combined schematically for illustration, but that theantenna and receiver may be separately located components, and that theantenna may be a GPS patch antenna or a helical antenna. The electroniccomponents further include I/O ports 470 connected to processor 410 vialine 475.

FIG. 4B is a block diagram of one embodiment for the electroniccomponents within the hardware of FIGS. 3A-3C and utilized by the GPSintegrated PDA 310 according to the teachings of the present invention.The electronic components shown in FIG. 4B include a processor 436 whichis connected to the GPS antenna 414 through GPS receiver 438 via line441. The processor 436 interacts with an operating system (such asPalmOS; Pocket PC) that runs selected software depending on the intendeduse of the PDA 310. Processor 436 is coupled with memory 442 such as RAMvia line 444, and power source 446 for powering the electroniccomponents of PDA 310. The processor 436 communicates with touchsensitive display screen 426 via data line 448.

The electronic components further include two other input sources thatare connected to the processor 436. Control buttons 428 are connected toprocessor 436 via line 451 and a map data cartridge 433 inserted intocartridge bay 432 is connected via line 452. A conventional serial I/Oport 454 is connected to the processor 436 via line 456. Cellularantenna 416 is connected to cellular transceiver 458, which is connectedto the processor 436 via line 466. Processor 436 is connected to thespeaker/headphone jack 434 via line 462. The PDA 310 may also include aninfrared port (not shown) coupled to the processor 436 that may be usedto beam information from one PDA to another.

As will be understood by one of ordinary skill in the art, theelectronic components shown in FIGS. 4A and 4B are powered by a powersource in a conventional manner. As will be understood by one ofordinary skill in the art, different configurations of the componentsshown in FIGS. 4A and 4B are considered within the scope of the presentinvention. For example, in one embodiment, the components shown in FIGS.4A and 4B are in communication with one another via wireless connectionsand the like. Thus, the scope of the navigation device of the presentinvention includes a portable electronic navigational aid device.

Using the processing algorithms of the present invention, the deviceselects an appropriate starting point for performing a new routecalculation and the device recognizes when the device has deviated fromthe route stored in memory. The device then uses those electroniccomponents to calculate a new route to navigate to the desireddestination. According to the teachings of the present invention, thedevice adjusts a starting point for the new route calculation to alocation forward along a current thoroughfare on which the device islocated or traveling such that the location is at or forward of thedevice at a time when the new route calculation is completed. In otherwords, the device adjusts a starting point for the new route calculationto a location forward along a current thoroughfare on which the deviceis located or traveling such that the device is on the route at a timewhen the new route calculation is completed. According to the teachingsof the present invention, the device incorporates these and otherfunctions as will be explained in more detail below in connection withFIGS. 6 and 7.

FIG. 5 is a block diagram of an embodiment of a navigation system whichcan be adapted to the teachings of the present invention. The navigationsystem includes a server 502. According to one embodiment, the server502 includes a processor 504 operably coupled to memory 506, and furtherincludes a transmitter 508 and a receiver 510 to send and receive data,communication, and/or other propagated signals. The transmitter 508 andreceiver 510 are selected or designed according to the communicationrequirements and the communication technology used in the communicationdesign for the navigation system. The functions of the transmitter 508and the receiver 510 may be combined into a single transceiver.

The navigation system further includes a mass data storage 512 coupledto the server 502 via communication link 514. The mass data storage 512contains a store of navigation data. One of ordinary skill in the artwill understand, upon reading and comprehending this disclosure, thatthe mass data storage 512 can be separate device from the server 502 orcan be incorporated into the server 502.

In one embodiment of the present invention, the navigation systemfurther includes a navigation device 516 adapted to communicate with theserver 502 through the communication channel 518. According to oneembodiment, the navigation device 516 includes a processor and memory,as previously shown and described with respect to the block diagram ofFIGS. 4A and 4B. Furthermore, the navigation device 516 includes atransmitter 520 and receiver 522 to send and receive communicationsignals through the communication channel 518. The transmitter 520 andreceiver 522 are selected or designed according to the communicationrequirements and the communication technology used in the communicationdesign for the navigation system. The functions of the transmitter 520and receiver 522 may be combined into a single transceiver.

Software stored in the server memory 506 provides instructions for theprocessor 504 and allows the server 502 to provide services to thenavigation device 516. One service provided by the server 502 involvesprocessing requests from the navigation device 516 and transmittingnavigation data from the mass data storage 512 to the navigation device516. According to one embodiment, another service provided by the server502 includes processing the navigation data using various algorithms fora desired application, and sending the results of these calculations tothe navigation device 516.

The communication channel 518 is the propagating medium or path thatconnects the navigation device 516 and the server 502. According to oneembodiment, both the server 502 and the navigation device 516 include atransmitter for transmitting data through the communication channel anda receiver for receiving data that has been transmitted through thecommunication channel.

The communication channel 518 is not limited to a particularcommunication technology. Additionally, the communication channel 518 isnot limited to a single communication technology; that is, the channel518 may include several communication links that use a variety oftechnology. For example, according to various embodiments, thecommunication channel is adapted to provide a path for electrical,optical, and/or electromagnetic communications. As such, thecommunication channel includes, but is not limited to, one or acombination of the following: electrical circuits, electrical conductorssuch as wires and coaxial cables, fiber optic cables, converters,radio-frequency (RF) waveguides, the atmosphere, and empty space.Furthermore, according to various embodiments, the communication channelincludes intermediate devices such as routers, repeaters, buffers,transmitters, and receivers, for example.

In one embodiment, for example, the communication channel 518 includestelephone and computer networks. Furthermore, in various embodiments,the communication channel 516 is capable of accommodating wirelesscommunication such as radio frequency, microwave frequency and infraredcommunication, and the like. Additionally, according to variousembodiments, the communication channel 516 accommodates satellitecommunication.

The communication signals transmitted through the communication channel518 include such signals as may be required or desired for a givencommunication technology. For example, the signals may be adapted to beused in cellular communication technology, such as time divisionmultiple access (TDMA), frequency division multiple access (FDMA), codedivision multiple access (CDMA), global system for mobile communications(GSM), and the like. Both digital and analog signals may be transmittedthrough the communication channel 518. According to various embodiments,these signals are modulated, encrypted and/or compressed signals as maybe desirable for the communication technology.

The mass data storage includes sufficient memory for the desirednavigation application. Examples of mass data storage include magneticdata storage media such as hard drives, optical data storage media suchas CD ROMs, charge storing data storage media such as Flash memory, andmolecular memory, such as now known or hereinafter developed.

According to one embodiment of the navigation system, the 502 serverincludes a remote server accessed by the navigation device 516 through awireless channel. According to other embodiments of the navigationsystem, the server 502 includes a network server located on a local areanetwork (LAN), wide area network (WAN), a virtual private network (VPN)and server farms.

According to another embodiment of the navigation system, the server 502includes a personal computer such as a desktop or laptop computer. Inone embodiment, the communication channel 518 is a cable connectedbetween the personal computer and the navigation device. According toone embodiment, the communication channel 518 is a wireless connectionbetween the personal computer and the navigation device 516.

FIG. 5 presents yet another embodiment for a collective set ofelectronic components adapted to the present invention. As one ofordinary skill in the art will understand upon reading and comprehendingthis disclosure, the navigation system of FIG. 5 is adapted to thepresent invention in a manner distinguishable from that described andexplained in detail in connection with FIGS. 4A and 4B.

That is, the navigational system 500 of FIG. 5 is likewise adapted toprovide an electronic navigational aid device 516 with route calculationcapabilities. In this embodiment, the processor 504 in the server 502 isused to handle the bulk of the system's processing needs. The massstorage device 512 connected to the server can include volumes morecartographic and route data than that which is able to be maintained onthe navigational device 516 itself. In this embodiment, the server 502processes the majority of a device's travel along the route using a setof processing algorithms and the cartographic and route data stored inmemory 512 and can operate on signals, e.g. GPS signals, originallyreceived by the navigational device 516. Similar to the navigationaldevice of FIGS. 4A and 4B, the navigation device 516 in system 500 isoutfitted with a display 524 and GPS capabilities 526.

As described and explained in detail in connection with FIGS. 4A and 4B,the navigation system of FIG. 5 uses processing algorithms select anappropriate starting point for performing a new route calculation. And,the system uses the processing algorithms to recognize when the devicehas deviated from the route and to perform a new route calculation. Thesystem then uses the electronic components shown in FIG. 5 to select theappropriate starting point and calculate a new route for navigating thedevice 516 to the desired destination. As one of ordinary skill in theart will understand upon reading and comprehending this disclosure, auser of the navigation device 516 can be proximate to or accompanyingthe navigation device 516. The invention however, is not so limited.

According to the teachings of the present invention, the system adjustsa starting point for the new route calculation to a location forwardalong a current thoroughfare on which the device is located or travelingsuch that the location is at or forward of the device at a time when thenew route calculation is completed. In other words, the device adjusts astarting point for the new route calculation to a location forward alonga current thoroughfare on which the device is located or traveling suchthat the device is on the route at a time when the new route calculationis completed. The navigation device 516 of the present inventionincludes a portable electronic navigational aid device. In oneembodiment, the portable electronic navigational aid device includes apersonal digital assistant (PDA). In one embodiment, the portableelectronic navigational aid device includes a wireless communicationsdevice.

The features and functionality explained and described in detail abovein connection with the device of FIGS. 4A and 4B are likewise availablein the system 500 of FIG. 5. That is, in one embodiment the navigationdevice 516 further provides audio and visual cues to aid the navigationalong the route.

FIG. 6 is a flow diagram of one embodiment of a navigation aid methodaccording to the teachings of the present invention. The navigation aidmethod includes a method for performing a route calculation within anavigation device or navigation system as described and explained indetail above in connection with FIGS. 4A, 4B, and 5. And, as describedabove, a processor is used for processing signals which include inputdata from input devices, e.g. keypads, other input keys, or otherinputs, GPS signals from GPS components, and data received from I/Oports in order to perform the methods described herein. In theembodiment shown in FIG. 6, the navigation aid method for performing aroute calculation includes detecting when a navigation device hasdeviated from a first route of navigation and calculating the device'scurrent location in block 610. The device's travel speed is calculatedin block 620. A calculation time is determined for processing a secondroute of navigation from the device's current location to a desireddestination in block 630. In one embodiment, the calculation time forprocessing a second route of navigation is estimated based on a distancefrom the device's current location to the desired destination. In oneembodiment, the calculation time is estimated base on a complexity ofthe thoroughfares from the device's current location to the desireddestination. In one embodiment, the calculation time for processing thesecond, or new route of navigation is determined as a time equal to orgreater than an actual previous calculation time. Subsequently, in block640, a starting point for the second route of navigation is selectedbased on the device's travel speed and the determined calculation timefor processing the second, or new route. Once the second, or new routehas been determined in block 645, the method proceeds to block 650 andnavigates the route. As one of ordinary skill in the art will understandupon reading and comprehending this disclosure, the method embodimentdescribed in FIG. 6 is repeatable, returning to block 610 in order tocontinually assess whether a then current position of the navigationdevice has deviated from the route. In one embodiment of the presentinvention, detecting when the device has deviated from the first routeof navigation and calculating the device's current location includesusing a global positioning system. According to the teachings of thepresent invention, selecting a starting point for the second route ofnavigation includes selecting a starting point forward on a currentthoroughfare on which the device is located or traveling such that thedevice is on the route at a time when the new route calculation iscompleted. In one embodiment, selecting a starting point for the secondroute can include a starting point located at an end of a currentthoroughfare on which the device is traveling.

In one method embodiment of the present invention, the device operateson data indicative of a set of travel habits of the device on each ofthe plurality of types of thoroughfares and stores the travel habit datain the memory. In one embodiment of the present invention, the travelhabit data includes data relating to the thoroughfare classification,the speed classification of the thoroughfare, the time of day, and thehistorical travel speed of the device on the particular thoroughfare. Inthe invention, the device regularly calculates the device's currentposition. The display continuously displays the device's position anduses audio and/or visual instructions to navigate to the starting pointof the new route calculation as well as to navigate along the new route.

According to the teachings of the present invention, and as used herein,the device travel speed includes an estimated device travel speed, alearned device travel speed, and a current device travel speed. As usedherein, a learned device travel speed includes travel speed data that isobtained from the data indicative of a set of travel habits of thedevice on each of the plurality of types of thoroughfares. As usedherein, an estimated travel speed includes travel speed data that isobtained from data indicative of a thoroughfare's classification typesuch as an interstate, city street, residential road and the like, andincludes travel speed data that is obtained from the data indicative ofa thoroughfare's speed classification such as a 25 mph, 55 mph, 75 mphor other roadway speed class on each of the plurality of types ofthoroughfares. In one embodiment according to the teachings of thepresent invention, calculating the device's travel speed includes usinga device travel speed which is the greater of the device's currenttravel speed and the device's learned travel speed or estimated travelspeed.

In one method embodiment, in order to perform the new route calculation,the device calculates a length of a thoroughfare on which the device iscurrently traveling and calculates the device's travel speed tocalculate how far the device will travel on the current thoroughfarebefore a route calculation can be completed in order to adjust thestarting point.

According to the teachings of the present invention, the device of thepresent invention includes a portable electronic navigational aiddevice. In one embodiment, the portable electronic navigation aid deviceincludes a portable vehicle, or automobile navigation device. In oneembodiment, the portable electronic navigational aid device includes apersonal digital assistant (PDA). In one embodiment, the portableelectronic navigational aid device includes a wireless communicationsdevice.

Another method embodiment of the present invention includes anelectronic navigational aid device with route calculation capabilities.As described above the electronic components include a processor and amemory connected to the processor. In this embodiment, the memory hasresident cartographic data and a route stored therein to navigate thedevice from a beginning position to a desired destination. As before,the cartographic data including data indicative of thoroughfares of aplurality of types. A display is connected to the processor and capableof displaying the cartographic data, the route to the desireddestination, and the device's position. The device processes travelalong the route and provides the device's location data to the display.In one embodiment, the device further provides audio and visual cues toaid navigation along the route.

In the invention, the method includes recognizing when the device hasdeviated from the route and calculating a new route to navigate thedevice to the desired destination. The method includes adjusting astarting point for the new route calculation to a location forward alonga current thoroughfare on which the device is traveling. In calculatingthe new route the device calculates the device's travel speed tocalculate how far the device will travel on the current thoroughfarebefore a the new route calculation can be completed. In one embodiment,in calculating the new route the device calculates a distance from thedevice's current position to the desired destination to estimate a firstroute calculation time. The device then uses a travel speed and thefirst route calculation time to set the starting point for the new routecalculation.

According to the teachings of the present invention, if the device isnot determined to be on the new route after an actual first routecalculation time then the device uses a second route calculation timeand the device's travel velocity to set a new starting point, on thecurrent thoroughfare on which the device is traveling, for another newroute calculation. In one embodiment, the second route calculation timeis equal to or greater than an actual first route calculation time.

In one embodiment of the present invention, the starting point is set atthe end of the current thoroughfare on which the device is traveling.However, as will be understood by one of ordinary skill in the art uponreading this disclosure, there will be instances for which setting thestarting point at the end of the current thoroughfare will notadequately set the starting point at a location forward of the devicebased on the device's travel speed and the necessary route calculationtime. In those instances, the device of the present invention uses a setof criteria to analyze adjacency information and determine a straightestpath in order to adjust the starting point for the new route calculationto, or sufficiently forward of, a location at which the device is likelyto be at the end of the route calculation time, such that the device inon the route at a time when the new route calculation is completed. Asused herein, the term adjacency information, or adjacencies, is intendedto include any thoroughfare which intersects the current thoroughfare onwhich the device is traveling. Every place two thoroughfares intersectis termed a node. Thus, every node on a given thoroughfare connects thatthoroughfare to an adjacency, or adjacent thoroughfare.

FIG. 7 is a flow diagram of another embodiment of a navigation aidmethod according to the teachings of the present invention. Thenavigation aid method includes a method for performing a routecalculation within a navigation device or navigation system such asdescribed and explained in detail above in connection with FIGS. 4A, 4B,and 5. And, as described above, a processor is used for processingsignals which include input data from user input devices, e.g. keypadsor other inputs, GPS signals from GPS device/system components, and datareceived from I/O ports in order to perform the methods describedherein.

As shown in FIG. 7, the navigation aid method for performing a routecalculation includes determining whether the navigation device is movingand cartographically- or map-matched to one of a plurality ofthoroughfares in block 710. In one embodiment as used herein,cartographically- or map-matched is intended to imply determiningwhether the device is located on a thoroughfare. In one embodiment,determining whether the navigation device is moving andcartographically- or map-matched to one of a plurality of thoroughfaresincludes using a GPS. According to the method, if the device is notcartographically- or map-matched to a thoroughfare then the methoddetermines the thoroughfare on which the device is most likely to belocated. As one of ordinary skill in the art will understand uponreading this disclosure, the method includes retrieving a currentposition of the navigation device, cartographic data for a plurality ofthoroughfares in a network, and data for a desired destination.

If the device is not moving, then once the current position of thenavigation device is determined the method proceeds to block 750 andproceeds to calculate a route using a current position of thenavigational device as a starting point for the route calculation.

On the other hand, if the navigation device is moving, the methodproceeds to block 720 where the method determines a travel speed orvelocity of the navigation device and determines a route calculationtime for providing a route from the current geographic position of thenavigation device to a desired destination. In one embodiment, themethod estimates a route calculation time for providing a route from thecurrent geographic position of the navigation device to a desireddestination. The method in block 720 for determining a travel speed orvelocity of the navigation device and determining a route calculationtime includes that which has been described above in connection withFIG. 6. The method in block 720 includes using this information tocalculate a distance predicting how far the navigation device willtravel, along a thoroughfare on which the navigation device is moving,within the determined route calculation time such that the device is onthe route at a time when the new route calculation is completed.

In block 730, the method adjusts a starting point for the new routecalculation to a location forward along a current thoroughfare on whichthe device is traveling. In one embodiment, according to the teachingsof the present invention, the method adjusts the starting point for thenew route calculation forward along the current thoroughfare on whichthe device is traveling a distance equal to the distance calculated inblock 720. In one embodiment, the method adjusts the starting point forthe new route calculation forward along to the end of the currentthoroughfare on which the device is traveling.

In block 740 the method includes determining whether a straightest pathalong the current thoroughfare on which the device is traveling isascertainable in order to adjust the location of the starting pointforward of the device. As one of ordinary skill in the art willunderstand upon reading this disclosure, the current thoroughfare onwhich the device is traveling can be approaching a node or intersectionof streets such that there are a number of adjacencies approaching inthe direction of travel. If a straightest path along the currentthoroughfare on which the device is traveling is ascertainable in orderto adjust the location of the starting point forward of the device suchthat the device will be on the route at a time when the new routecalculation is completed, then the method proceeds to block 750 andcalculates a new route using a starting point location which will be ator forward of the device at a time when the new route calculationcompletes.

However, in some instances where the device is approaching a node orintersection of streets, such that there are a number of adjacenciesapproaching in the direction of travel, a straightest path along thecurrent thoroughfare on which the device is traveling is not immediatelyascertainable. Therefore, simply adjusting the starting point for thenew route calculation forward, even to the end of the currentthoroughfare, will not suffice or does not provide an adequate distance,based on the travel speed of navigation device and the determined newroute calculation time, such that the location of the starting pointwill be at or forward of the device at the time the new routecalculation completes.

When the straightest path is not immediately ascertainable, the methodproceeds to block 760 where the method evaluates a set of adjacencycriteria to determine a straightest path and locate the starting pointfor the new route calculation somewhere along a chosen adjacency suchthat the starting point for the new route calculation will be at orforward of the device at a time when the new route calculationcompletes. According to the teachings of the present invention, the setof adjacency criteria includes, but is not limited to, the degree ofturn angles between the thoroughfare on which the device is located andadjacent thoroughfares connected thereto by a node, thoroughfare names,thoroughfare classifications, speed classification of the thoroughfares,and other criteria of the like.

As stated, as used herein, the term adjacency information, oradjacencies, is intended to include any thoroughfare which intersectsthe current thoroughfare on which the device is traveling. Every placetwo roads intersect is termed a node. Thus, every node on a giventhoroughfare connects that thoroughfare to an adjacency, or adjacentthoroughfare. Once the straightest path along the current thoroughfareon which the device is traveling is ascertainable in order to adjust thelocation of the starting point forward of the device, such that thedevice will be on the route at a time when the new route calculation iscompleted, then the method proceeds to block 750 where the methodcalculates the new route.

As shown in FIG. 7, once a new route has been calculated in block 750,the method proceeds to block 770. In block 770 the method determineswhether the device location is on the calculated route. If so, themethod proceeds to block 780 and begins navigating the new route,including navigating the device to the starting point for the new route.In one embodiment, the method navigates the new route using both visualand audio cues.

Alternatively, according to the teachings of the present invention, ifthe device location is not on the calculated route then the methodproceeds to block 790 and retrieves the current position of thenavigation device. Next, in block 795 the method retrieves a travelvelocity for the device and additionally retrieves an actual calculationtime which was required to perform the previous new route calculation.

According to the teachings of the present invention, the method thenreturns from block 795 to block 720 and repeats the sequence describedabove until a new route calculation has been completed with a startingpoint for the new route such that the device is on the new route at thetime the new route calculation completes and eventually proceeds toblock 780 to start navigating the route.

In some embodiments, the methods provided above are implemented as acomputer data signal embodied in a carrier wave or propagated signal,that represents a sequence of instructions which, when executed by aprocessor, such as processor 410 in FIGS. 4A and 4B or processor 504 inFIG. 5, cause the processor to perform the respective method. In otherembodiments, methods provided above are implemented as a set ofinstructions contained on a computeraccessible medium, such as memory430 in FIGS. 4A and 4B or mass storage device 512 in FIG. 5, capable ofdirecting a processor, such as processor 410 in FIGS. 4A and 4B orprocessor 504 in FIG. 5, to perform the respective method. In varyingembodiments, the medium is a magnetic medium, an electronic medium, oran optical medium.

As one of ordinary skill in the art will understand upon reading thisdisclosure, the electronic components of device 400 shown in FIGS. 4Aand 4B and components of the system 500 shown in FIG. 5 can be embodiedas computer hardware circuitry or as a computer-readable program, or acombination of both. In another embodiment, system 500 is implemented inan application service provider (ASP) system.

The system of the present invention includes software operative on aprocessor to perform methods according to the teachings of the presentinvention. One of ordinary skill in the art will understand, uponreading and comprehending this disclosure, the manner in which asoftware program can be launched from a computer readable medium in acomputer based system to execute the functions defined in the softwareprogram. One of ordinary skill in the art will further understand thevarious programming languages which may be employed to create a softwareprogram designed to implement and perform the methods of the presentinvention. The programs can be structured in an object-orientation usingan object-oriented language such as Java, Smalltalk or C++, and theprograms can be structured in a procedural-orientation using aprocedural language such as COBOL or C. The software componentscommunicate in any of a number of means that are well-known to thoseskilled in the art, such as application program interfaces (A.P.I.) orinterprocess communication techniques such as remote procedure call(R.P.C.), common object request broker architecture (CORBA), ComponentObject Model (COM), Distributed Component Object Model (DCOM),Distributed System Object Model (DSOM) and Remote Method Invocation(RMI). However, as will be appreciated by one of ordinary skill in theart upon reading this disclosure, the teachings of the present inventionare not limited to a particular programming language or environment.

CONCLUSION

The above systems, devices and methods have been described, by way ofexample and not by way of limitation, with respect to improvingaccuracy, processor speed and ease of user interaction with a navigationdevice. That is, the systems, devices and methods provide for anavigational route planning device which is more efficient and accuratethan current low cost systems, without requiring the more expensivesystem resources. The systems, devices and methods of the presentinvention offer an improved navigational route planning device whichprovide more understandable, accurate and timely route calculationcapabilities.

Although specific embodiments have been illustrated and describedherein, it will be appreciated by those of ordinary skill in the artthat any arrangement which is calculated to achieve the same purpose maybe substituted for the specific embodiment shown. This application isintended to cover any adaptations or variations of the presentinvention. It is to be understood that the above description is intendedto be illustrative, and not restrictive. Combinations of the aboveembodiments, and other embodiments will be apparent to those of skill inthe art upon reviewing the above description. The scope of the inventionincludes any other applications in which the above systems, devices andmethods are used. The scope of the invention should be determined withreference to the appended claims, along with the full scope ofequivalents to which such claims are entitled.

What is claimed is:
 1. An electronic navigational aid device with routecalculation capabilities, comprising: a processor; a memory adapted tocommunicate with the processor, the memory having cartographic data anda desired destination, the cartographic data including data indicativeof thoroughfares of a plurality of types; a display connected to theprocessor and capable of displaying the cartographic data; wherein thedevice is adapted to calculate a route to navigate to the desireddestination; and wherein the device is adapted to adjust a startingpoint for the route calculation to an appropriate location such that thedevice is on the route at a time when the route calculation iscompleted.
 2. The device of claim 1, wherein the device determines dataindicative of a set of travel habits for the device on each of theplurality of types of thoroughfares and stores the travel habit data inthe memory.
 3. The device of claim 1, wherein the device regularlycalculates the device's current position and processes the device'stravel along the route.
 4. The device of claim 3, wherein the displaycontinuously displays the device's position and uses audio instructionsto navigate to the starting point of the route calculation as well as tonavigate along the route.
 5. The device of claim 1, wherein the devicedetermines a calculation time for processing the route and determines atravel speed for the device, and wherein the device uses thisinformation to adjust the starting point for the route calculation. 6.The device of claim 5, wherein the travel speed for the device isdetermined based on the greater of a current travel speed of the deviceand either of a learned travel speed or an estimated travel speed of thedevice for a current thoroughfare on which the device is located ortraveling.
 7. The device of claim 1, wherein the device includes aportable electronic navigational aid device.
 8. The device of claim 7,wherein the portable electronic navigational aid device includes apersonal digital assistant (PDA).
 9. The device of claim 7, wherein theportable electronic navigational aid device includes a wirelesscommunications device.
 10. An electronic navigational aid device withroute calculation capabilities, comprising: a processor; a memory incommunication with the processor, the memory having cartographic dataand a route stored therein to navigate from a beginning position to adesired destination, the cartographic data including data indicative ofthoroughfares of a plurality of types; a display in communication withthe processor and capable of displaying the cartographic data, the routeto the desired destination, and the device's position; wherein thedevice processes the device's location and provides location data to thedisplay; and wherein the device recognizes when the device has deviatedfrom the route and calculates a new route to navigate to the desireddestination, wherein the device adjusts a starting point for the newroute calculation to an appropriate location such that the device is onthe new route at a time when the route calculation is completed.
 11. Thedevice of claim 10, wherein in calculating the new route the devicedetermines a travel speed of the device to determine how far the devicewill travel on the current thoroughfare before a the new routecalculation can be completed.
 12. The device of claim 11, wherein incalculating the new route the device estimates a first route calculationtime for processing the new route based on a complexity of thethoroughfares from a current position of the device to the desireddestination, and wherein the device uses the determined travel speed ofthe device and the first route calculation time to adjust the startingpoint for the new route calculation.
 13. The device of claim 12, whereinif the device is not on the new route after an actual first routecalculation time then the device uses a second route calculation timeand the device's travel speed to set a new starting point for anothernew route calculation.
 14. The device of claim 13, wherein the secondroute calculation time is equal to or greater than an actual first routecalculation time.
 15. The device of claim 10, wherein the device uses aset of criteria to analyze adjacency information and to determine astraightest path in order to adjust the starting point for the new routecalculation.
 16. The device of claim 10, wherein the starting point isat an end of a current thoroughfare on which the device is traveling.17. A navigation aid method for performing a route calculation,comprising: determining a travel speed of a navigation device;estimating a calculation time for processing a first route of navigationfrom a first location of the device to a desired destination; andselecting a starting point for the first route of navigation based onthe determined travel speed of the device and the estimated calculationtime for processing the first route of navigation.
 18. The method ofclaim 17, wherein estimating a calculation time for processing the firstroute of navigation includes assessing a complexity of a route solutionbetween the first location of the device and the desired destination.19. The method of claim 17, wherein the method further includesdetecting when the navigation device has deviated from the first routeof navigation, determining a new second location of the device, andestimating a calculation time for processing a second route ofnavigation from the second location of the device to the desireddestination.
 20. The method of claim 19, wherein detecting when thedevice has deviated from the first route of navigation and determiningthe second location of the device includes using a,global positioningsystem.
 21. The method of claim 19, wherein estimating a calculationtime for processing the second route of navigation includes using acalculation time which is equal to or greater than an actual previousroute calculation time.
 22. The method of claim 16, wherein selecting astarting point includes using a set of criteria to analyze adjacencyinformation and determine a straightest path in order to adjust thestarting point.
 23. A navigation system, comprising: a mass data storageadapted to store navigation data; a server having a processor andmemory, wherein the server is adapted to communicate with the mass datastorage; and a navigation device adapted to communicate with andretrieve navigation data from the server via a communication channel,wherein the navigation device includes: a processor; a display connectedto the processor; and a memory connected to the processor, the memoryhaving cartographic data and a route to a desired destination storedtherein, the cartographic data including data indicative ofthoroughfares of a plurality of types; wherein the system processes thenavigation device's travel along the route; wherein the systemrecognizes when the device has deviated from the route and is adapted tocalculate a new route to navigate the device to the desired destinationusing an exchange of data, via the communication channel, between theserver, the mass storage device and the navigation device; and whereinthe system is adapted to adjust a starting point for the new routecalculation to an appropriate location such that the device is on thenew route at a time when the route calculation is completed.
 24. Thenavigation system of claim 23, wherein the communication channelincludes a wireless channel.
 25. The navigation system of claim 23,wherein the server includes a remote server.
 26. The navigation systemof claim 23, wherein the server includes a processor adapted to respondto a request from the navigation device by performing calculations onthe navigation data and transmitting results to the navigation device.27. The navigation system of claim 23, wherein the navigation deviceadapted to communicate with and retrieve navigation data from the serverusing streaming data.
 28. The navigation system of claim 23, wherein thenavigation device adapted to communicate with and retrieve navigationdata from the server using cellular communication technology.